Poor quality graphics from PDF conversion

[Chris Ramsay]

I have experienced similar problems recently - not sure exactly what software you are all using, but the clue is PNG graphics being poor when transparency is enabled.

The underlying issue is that low level routines within GDI (Graphics Display Interface) of Windows discard the alpha channel of graphics files. The alpha channel is what provides the transparency information for PNG and GIF files. Without the alpha channel being handled properly, the edges of the image go all chunky.

JPEGs do not have an alpha channel so are not a problem.

It all depends on the software you are using - I have found most freeware PDF converters all have the same problem. Not sure about the inbuilt converters of Office 2007.

To verify this is the problem your are having, take your PNG source image, convert it to a GIF with no transparency and no dithering, put it back in your Word document and try again - you will probably find your PDF conversion is now fine (it was for me).

If you Google something like "GDI alpha channel", you will find endless other chatter about this issue with Windows.

Software that uses it's own internal graphics routines (not the Windows routines) for image conversion should be fine ...

Or use a Mac !

 

[Ben Martin]

I have had this problem for some time, and it is incredibly frustrating. You would think that a beast like Adobe would support the office processing giant that is Microsoft. However, there can be no simple option as: "Make images in the PDF exactly the same as I see them on my screen whilst in Office" in the PDF maker (which would be a life saver).

I have found a solution though. I tried the Microsoft PDF Add-In, which allows you to publish to a PDF (the add-in was created by microsoft, so I assumed it would integrate without any problems). This created a PDF that looks exactly the same as my Office 2007 document at 100% (which is exactly what I wanted). Most of the images zoom decently too (looks fine at 75% + 125%).

Here is a link to the add-in:
http://download.microsoft.com/download/b/5/3/b5370004-d59d-493f-b005-2299ffca8596/SaveAsPDF.exe

 

[Shane Burke]

Checking the option to use ISO 19005-1 compliant (PDF/A) worked fine for me when the graphic doesn't include transparency. I was having this same issue with basic, non-transparent graphics regardless of format (PNG, BMP, JPG, TIF, etc). Checking that option generated a PDF that looks identical to the Word document.

 

[georgegeranium]

Checking PDF/A making the output quality very low on PDF. I rather unchecked it. More guide here: http://www.squidoo.com/ms-word-2010-low-image-quality-fixed

 

[PD FFFF]

Using Word 2007:

My situation is that we use PNG images of a person's signature, and company logo, which are 600 dpi, and part of a Word mail merge document. Printing the actual word document, the images and signatures are crisp. However, doing Save-As to PDF and then printing the PDF, the printed image quality is much worse.

I've tried setting the "No Compression" option in Word, I've added the no compression flag to the registry, I've tried using the Word to PDF add-in... all of which do not preserve the original image.

Also, another problem with printing the PDF is the images have a light gray box behind them. I think what happens is Word down-samples the image into the PDF, then the printer drivers do a poor job of interpolating the down-sampled image. Our printer is RICOH 4000, I'm going to talk to them about upgrading the printer drivers to fix that issue.

I've done the following test using PNG, JPG and GIF versions of a signature image:
1) Open word
2) Insert picture from file
3) Save As PDF

The resulting image in the PDF is always down-sampled. It's really annoying.

Alternatively, another test I've done is:
1) Open Word
2) Insert Picture from file
3) Print to Adobe PDF printer
4) Set highest quality setting

The above produces a PDF containing a higher quality image, but the size of the PDF is 1 MB, 10 times larger than it should be. Some clients, we email the PDF files, some clients, we print and mail the reports. For archival purposes, it's also nice to have smaller files, especially when creating tens of thousands of files every 3 months.

I've worked with the PostScript language, and know the basics of how to encode an image in ps format. I don't understand why MS Word can't do the same thing.

 

[Suzanne S. Barnhill]

If you use the Adobe add-in for Word (instead of the Microsoft one), with
Smallest File Size or Standard selected, do you have the same problem?

--
Suzanne S. Barnhill
Microsoft MVP (Word)
Words into Type
Fairhope, Alabama USA
http://word.mvps.org